18389490 has 64 divisors (see below), whose sum is σ = 51231744. Its totient is φ = 4137408.

The previous prime is 18389471. The next prime is 18389513. The reversal of 18389490 is 9498381.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an alternating number because its digits alternate between odd and even.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13417 + ... + 14723.

It is an arithmetic number, because the mean of its divisors is an integer number (800496).

Almost surely, 2^18389490 is an apocalyptic number.

18389490 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18389490, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25615872).

18389490 is an abundant number, since it is smaller than the sum of its proper divisors (32842254).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18389490 is a wasteful number, since it uses less digits than its factorization.

18389490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1391.

The product of its (nonzero) digits is 62208, while the sum is 42.

The square root of 18389490 is about 4288.2968647238. The cubic root of 18389490 is about 263.9509493352.

The spelling of 18389490 in words is "eighteen million, three hundred eighty-nine thousand, four hundred ninety".